#!/usr/bin/perl
#
# ph2 by Tikiman, orig version by miff 
#
# this is probably way too much work for what it does, but some of the 
#  subroutines are ready to be used elsewhere - especially addDays(),
#  putDays(), and getExp().  

use Time::Local;

$file_of_interest = '/etc/shadow';


$users = loadUsers($file_of_interest); # load a array of users
$totusers = scalar(@$users); # number of users
$| = 1; # autoflush on
print "There are $totusers users on your system.\n";
print "Which user are you interested in?  Use Tab to cycle through partial matches:\n";
print "User: ";

$buf = '';

# This is the convoluted section for tab-completion
BACK: while($key = getone()) { # blocks til it gets a keystroke
    if (ord($key) == 9) { # its a tab
	if ($lasttab) { # if the last keystroke was also a tab...
	    for ($t = 0;$t < $totusers;$t++) { # loop in user array
		$user = $users->[$t];
		if ($user eq $buf) { # found the user that we just picked
		    $u = $t + 1;
		    while($users->[$u]) { # shift the next value down
			$users->[$t] = $users->[$u];
			$t++;
			$u = $t + 1;
		    }
		    $users->[$t] = $user; # append last user to user array
		}
	    }
	} else {
	    $oldbuf = $buf; # just hit tab - use new buffer to match
	}
	$lasttab = 1; # tag flag
	for ($t = 0;$t < $totusers;$t++) { # loop through users
	    $user = $users->[$t];
	    if ($user =~ /^$oldbuf(.*)$/) { # we have a match
		delLine($buf); # slurp out old buffer
		$buf = $oldbuf . $1; # keep new buffer
		print $buf; # display it
		next BACK; # end loop
	    }	    

	}
	
    } elsif ((ord($key) == 127) || (ord($key) == 8)) { # backspace of c-H
	$lasttab = '';
	$buf && ($buf = backSp($buf)); # back up if theres room
    } elsif (ord($key) == 10) { # return
	$user = $buf; # got the user
	print "\n";
	last BACK; # break out of loop
    } else {
	print "$key"; # print the thing
	$lasttab = 0;
	$buf .= $key; # add to buffer
    }
}

# get the number of days until user exipres
($got_user,$days) = getExp($user,$file_of_interest);

if ($got_user) { # got a user
	print "\n=================================\nUsername $user\n";
	if ($days) {
		print "Expiration date: " . days2date($days) . " \n";
	} else {
		print "Expiration date: None\n";
	}
	print "=================================\n\n";
} else { # no user
	die "No such user\n";
}

dMenu(); # display a menu

HUH: # in case bad value is inputed

chomp($selection = <>); # get selection number

$selection =~ s/^(\d*).*?$/$1/;
if ($selection == 1) { # pretty clear section
	$days || die "Sorry, there was no expiration date to add to\n";		
	print "How many days would you like to add? ";
	chomp($ndays = <STDIN>);
	($ndays =~ /^\d*$/) || die "Thats not a number!\n";
	addDays($user,$ndays,$file_of_interest); 
	print "You have succufully added $ndays days\n";
	print "New expiration date of $user is " . expDate($user,$file_of_interest) . "\n\n";
	exit;
} elsif ($selection == 2) { # pretty clear section
	$days || die "Sorry, there was no expiration date to add to\n";		
	print "How many months would you like to add? ";
	chomp($nmon = <STDIN>);
	($nmon =~ /^\d*$/) || die "Thats not a number!\n";
	addDays($user,$nmon * 30,$file_of_interest); 
	print "You have successfully added $nmon months\n";
	($got_user,$days) = getExp($user,$file_of_interest);
	print "New expiration date of $user is " . expDate($user,$file_of_interest) . "\n\n";
	exit;
} elsif ($selection == 3) { # less clear
	print "Enter the new expiration date in MM-DD-YYYY format:\n";
	chomp($ndate = <STDIN>);
	foreach $sval (('-',' ','/')) { # determines the best date seperator
		if (scalar(@splitdate = split($sval,$ndate))
			> 1) { @rsplit = @splitdate ;}
	}

	$rsplit[2] || die "Sorry, I don't understand that input\n";
	(($rsplit[0] >= 1) && ($rsplit[0] <= 12)) || die "Bad Month!\n";
	(($rsplit[1] >= 1) && ($rsplit[1] <= 31)) || die "Bad Day!\n";
	
	if (($rsplit[2] > -1) && ($rsplit[2] < 99)) { # prepends 20 to some years
		$rsplit[2] =~ s/^(\d)$/0$1/g;
		$rsplit[2] = "20" . $rsplit[2];
	}

	($rsplit[2] == "99") && ($rsplit[2] = "1999"); # prepends 19 to 99
	(($rsplit[2] >= 1999) && ($rsplit[2] <= 2030)) || die "Bad Year!\n";
	
	$rsplit[0]--;
	$rsplit[2] -= 1900;

	$newsecs = timelocal(0,0,20,$rsplit[1],$rsplit[0],$rsplit[2]);
	$newsecs /= 60 * 60 * 24; # calculate new days since 1770

	putDays($user,$newsecs,$file_of_interest);
	print "Set expiration date of $user to " . expDate($user,$file_of_interest) . "\n\n";
	exit;
} elsif ($selection == 4) {
	putDays($user,'',$file_of_interest);
	print "Removed epiration date of $user\n\n";
	exit;
} elsif ($selection == 5) {
	print "Ok, no problem\n\n";
	exit;
} else {
	print "Huh? \n";
	goto HUH;
}

# returns exp. date of user
sub expDate {
	($got_user,$days) = getExp($_[0],$_[1]);
	return(days2date($days));
}

# gets expiration date, returns a bool if it found a user even
# if there was no date
sub getExp {
	my($user,$file) = @_;
	open(SHADOW,$file) || die "Can't open\n";
	while (<SHADOW>) {
		chomp;
		split ':';
		if ($_[0] eq $user)  {    # we have our row
			close(SHADOW);
			$_[7] ? return("1",$_[7]) : return("1") ;
		}
	}
}

# slurps users into array and returns reference to that array
sub loadUsers {
	my($file) = @_;
	my @users;
	open(SHADOW,$file) || die "Can't open\n";
	while (<SHADOW>) {
		chomp;
		split ':';
		push(@users,$_[0]);
	}
	return(\@users);
}

# converts days since 1970 into a date
sub days2date {
	$date = localtime($_[0] * 60 * 60 * 24);
	$date =~ s/^\S* (.*) .*:.*:.* (.*)$/$1 $2/;
	return($date);
}

# displays menu
sub dMenu {
	print "Please select one of the following options:\n";
	print "1) Add days to user's account\n";
	print "2) Add months to user's account (30 days)\n";
	print "3) Set new expiration date\n";
	print "4) Remove expiration date\n";
	print "5) Exit\n\n";
}

# adds days to a users account
sub addDays {
	my($user,$days,$file) = @_;
	open(SHADOW,$file) || die "Can't open\n";
	open(OUTPUT,">/etc/$$.tmp");
	while(<SHADOW>) {
		if (/^($user:.*?:.*?:.*?:.*?:.*?:.*?):(.*?):(.*?$)/) {
			$old = $2;
			$old += $days;
			print OUTPUT "$1:$old:$3\n";
		}
		else {
			print OUTPUT $_;
		}
	}	
	close(SHADOW);
	close(OUTPUT);
	rename("/etc/$$.tmp",$file);
	chmod 0600, $file;
}

# sets the days in a users account
sub putDays {
	my($user,$days,$file) = @_;
	open(SHADOW,$file) || die "Can't open\n";
	open(OUTPUT,">/etc/$$.tmp");
	while(<SHADOW>) {
		if (/^($user:.*?:.*?:.*?:.*?:.*?:.*?):(.*?):(.*?$)/) {
			print OUTPUT "$1:$days:$3\n";
		}
		else {
			print OUTPUT $_;
		}
	}
	close(SHADOW);	
	close(OUTPUT);
	rename("/etc/$$.tmp",$file);
	chmod 0600, $file;
}

# section that lets you read 1 character from STDIN - uses term settings
# and closures

BEGIN {
    use POSIX qw(:termios_h);
    my ($term, $oterm, $echo, $noecho, $fd_stdin);
    $fd_stdin = fileno(STDIN);
    $term = POSIX::Termios->new();
    $term->getattr($fd_stdin);
    $oterm = $term->getlflag();
    $echo = ECHO | ECHOK | ICANON;
    $noecho = $oterm & ~$echo;    
    sub cbreak {
	$term->setlflag($noecho);
	$term->setcc(VTIME, 1);
	$term->setattr($fd_stdin, TCSANOW);
    }
    sub cooked {
	$term->setlflag($oterm);
	$term->setcc(VTIME, 0);
	$term->setattr($fd_stdin, TCSANOW);
    }
    sub getone {
	my $key = '';
	cbreak();
	sysread(STDIN, $key, 1);
	cooked();
	return $key;
    }
}

END { cooked() }

sub backSp {
    my $buf = shift;
    print chr(8) . " " . chr(8);
    $buf =~ s/.$//g;
    return($buf);
}

sub delLine {
    my $buf = shift;
    while($buf) {
	$buf = backSp($buf);
    }
}